Pacific/Johnston

Time zone identifier: Pacific/Johnston

Current civil offset: -10:00 (HST)

Current DST state: Observing Standard Time

First standard time adoption: Adopted on 1896-01-13

Local Mean Time (LMT): -10:31:26 based on geographic meridian

Total recorded transitions: 7 transitions across 4 distinct offsets

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Historical Offset Step Chart (1880 to Present)

-12:00 -11:00 -10:00 -9:00 -8:00 1880 1900 1920 1940 1960 1980 2000 2020

Text summary: Pacific/Johnston shifted between 4 distinct offsets from 1896-01-13 through the modern era.

Complete Transition History (7 Transitions)

UTC Instant Local Wall Time Shift Abbreviation DST Effect
1896-01-13T22:31:26Z 1896-01-13 12:01:26 -10:31:26 → -10:30 HST No gap
1933-04-30T12:30:00Z 1933-04-30 03:00:00 -10:30 → -09:30 HDT Yes gap
1933-05-21T21:30:00Z 1933-05-21 11:00:00 -09:30 → -10:30 HST No overlap
1942-02-09T12:30:00Z 1942-02-09 03:00:00 -10:30 → -09:30 HWT Yes gap
1945-08-14T23:00:00Z 1945-08-14 13:30:00 -09:30 → -09:30 HPT Yes offset-only
1945-09-30T11:30:00Z 1945-09-30 01:00:00 -09:30 → -10:30 HST No overlap
1947-06-08T12:30:00Z 1947-06-08 02:30:00 -10:30 → -10:00 HST No gap

Notes from the Maintainers

Source: backzone (Lines 1744 to 1745)
Johnston

Years on Record

Methodology Note: The 1970 Rule

tzdb guarantees accuracy for timestamps from 1970 onwards. Transitions prior to 1970 represent best-effort historical reconstructions.